The repair process of osteonecrosis after a transtrochanteric rotational osteotomy.

BACKGROUND: Many studies have reported the factors influencing the progression of collapse and development of osteoarthritis after a transtrochanteric rotational osteotomy. It is not well understood how the healing process of the osteonecrotic area occurs after this procedure. QUESTIONS/PURPOSES: We evaluated (1) the osteonecrotic area after a successful transtrochanteric rotational osteotomy radiographically; and (2) determined whether specific perioperative clinical and radiographic factors related to the difference(s) in the healing process after a transtrochanteric rotational osteotomy. METHODS: We retrospectively reviewed 64 patients (70 hips) among 402 patients (507 hips) who had a transtrochanteric rotational osteotomy between 1981 and 1996 and showed no evidence of progression of collapse or joint space narrowing at 10 years after the osteotomy. Forty-eight hips (45 patients) were males and 22 (19 patients) were females, with a mean age of 37 years (range, 12-57 years) at the time of surgery. An anterior rotational osteotomy was performed for 57 hips and a posterior rotational osteotomy was performed for 13 hips. We recorded various perioperative factors potentially influencing repair and assessed the radiographs at last followup for various features indicating repair. RESULTS: Ten years after the transtrochanteric rotational osteotomy, the osteonecrotic area in 50 hips (71%) had osteosclerotic changes radiographically (Group I), while 20 hips (29%) had normal bony architecture without sclerotic changes (Group II). We observed no difference between Groups I and II with regard to the age, gender, use of corticosteroids, etiology, and radiographic stage. CONCLUSIONS: Although the reason for this difference in the healing patterns remains unknown, this study indicates the majority of the hips showed osteosclerosis after a transtrochanteric rotational osteotomy, while approximately 30% of the hips showed a normal bony architecture.

Shape of the joint gap for 90 degrees and 120 degrees knee flexion after total knee arthroplasty.

BACKGROUND: The joint gap is set rectangular at 90 degrees flexion during total knee arthroplasty (TKA). However, the condition of the joint gap in deep knee flexion is obscure. METHODS: The method for obtaining a posteroanterior view radiograph of the knee at 90 degrees flexion (the epicondylar view) was modified, and a method to obtain an anteroposterior view radiograph at 120 degrees flexion (deep flexion view) was established. With this method, subjects lie on the radiography table with their thighs placed on a device so their lower legs hang down in neutral rotation with a 1.5-kg weight attached to the ankle. The joint gap angle and medial and lateral joint space widths were measured on epicondylar view and deep flexion view radiographs in 20 normal male subjects, 20 normal female subjects, and 20 subjects after TKA. RESULTS: The joint gap was almost rectangular at two flexion angles in normal subjects. In the implanted knees, the gap angle was 1.4 degrees varus +/- 3.3 degrees (mean +/- standard deviation), and no significant difference was found between medial and lateral joint space widths at 90 degrees flexion. In contrast, the gap angle was 2.5 degrees varus +/- 2.5 degrees and the lateral joint space width was significantly wider than the medial joint space width at 120 degrees flexion (P < 0.001). The gap angle was more varus with a significant difference in the implanted knees than that in the normal subjects at 120 degrees flexion (P < 0.001). CONCLUSIONS: The joint gap was trapezoidal with a wider lateral side at 120 degrees flexion even though it was almost rectangular at 90 degrees flexion after TKA.

Transtrochanteric posterior rotational osteotomy for osteonecrosis.

When osteonecrosis is located in the mid- to posterior region, we generally perform a transtrochanteric posterior rotational osteotomy. We retrospectively reviewed the clinical and radiographic results in 47 consecutive patients (51 hips) in whom we performed posterior rotational osteotomies. The average age was 37 years at the time of surgery. There were 30 male and 17 female patients. Thirty-six hips were ARCO Stage III, and 15 were Stage IV. Conversion to THA was defined as the failure end point. Three patients died and one was lost to followup. We were therefore able to follow 43 patients (46 of the 51 hips, or 90%) a minimum of 1.2 years (average, 12 years; range, 1.2-21 years). We used the Harris hip score for preoperative and most recent followup. The average preoperative Harris hip score of 52 points improved to an average of 84 at the latest followup. Radiographically, the osteonecrosis in 30 hips (65%) had no progressive collapse, and 13 (28%) showed osteoarthritic changes, but no patients underwent THA. A posterior rotational osteotomy appears useful for patients with extensive necrosis and advanced collapse.

Factors associated with pain and functional limitation in Japanese male patients with knee osteoarthritis.

The present study investigated factors associated with knee pain and functional limitation in knee OA patients. Subjects were 109 Japanese males who were newly diagnosed with knee OA at three university hospitals over a 1-year period. Knee pain and functional limitation in walking and climbing and/or descending stairs were selected as outcome measures. To assess factors associated with outcomes, we calculated odds ratios (OR) using logistic regression analysis. Taller height (> or =163 vs. <163 cm) showed a negative association with knee pain, "Pain on walking": OR = 0.08, 95% confidence interval = 0.01-0.79; "Pain on stairs": 0.25, 0.08-0.82. A significant characteristic related to a lesser degree of functional disability was alcohol consumption ("Waking distance": 0.34, 0.14-0.84; "Help on stairs": 0.21, 0.09-0.51). In the present study, knee pain was associated with shorter height in male Japanese patients with knee OA. Functional limitation was associated with no consumption of alcohol.

Clinical effect of bisphosphonate and vitamin D on osteoporosis: reappraisal of a multicenter double-blind clinical trial comparing etidronate and alfacalcidol.

As inhibitors of bone resorption, bisphosphonates and vitamin D derivatives have been extensively used for the treatment of osteoporosis in various parts of the world, but the clinical effects of these two groups of agents have rarely been compared in detail. A multicenter, prospective, double-blind controlled study was started comparing the effects of etidronate and alfacalcidol (1-alpha-hydroxycholecalciferol) in 414 patients with established osteoporosis from 36 centers. Among these patients, 135 were given 400 mg etidronate daily at bedtime for 2 weeks followed by 10 weeks off treatment, and this cycle was repeated four times along with a placebo indistinguishable from the alfacalcidol capsule daily throughout the 48 weeks of study (Group A, High Dose Etidronate Group). In 133 patients, 200 mg etidronate was used instead of 400 mg (Group B, Low Dose Etidronate Group). In 138 patients, 1 microg alfacalcidol was given daily throughout the 48-week study period along with a placebo indistinguishable from the etidronate tablet in four separate periods of 2 weeks (Group C, Control Group). Dual-energy X-ray absorptiometry of the lumbar spine (L2-L4) was performed before the beginning of the study and every 12 weeks thereafter. Changes in spinal deformity were also assessed based on the lateral thoracic and lumbar spine X-ray films taken before and after the study. The lumbar spine bone mineral density (BMD) changes were +3.4% +/- 0.6% (mean +/- SEM) in Group A, +2.4% +/- 0.5% in Group B, and -0.5% +/- 0.4% in Group C, the former two being significantly higher than the last. New occurrence of spinal compression fracture was also significantly reduced in Group A compared to Group C. In patients without previous fracture at entry, incident fracture was 10.2% in Group C, but 0% in Groups A and B. In patients with prevalent fracture at entry, corresponding figures were 21.5% (Group C), 12.0% (Group A), and 13.2% (Group B), respectively. Alfacalcidol maintained lumbar spine BMD, preventing a decrease for 48 weeks, and etidronate significantly increased it further, demonstrating its usefulness in the treatment of established osteoporosis.

Factors associated with functional limitation in stair climbing in female Japanese patients with knee osteoarthritis.

BACKGROUND: Osteoarthritis (OA) of the knee is a common form of arthritis, and affects quality of life. We investigated factors associated with functional limitation in stair climbing among female Japanese patients with knee OA. As weight is a known risk factor for knee OA, we focused on body weight at 40 years of age, and examined the association with present weight, past weight, and weight change. METHODS: Subjects were 360 Japanese women aged 40-92 years who were newly diagnosed with knee OA at 3 university hospitals over a 1-year period. Factors associated with the severity of functional limitation in stair climbing were assessed by calculating odds ratios (OR) using the proportional odds model in logistic regression. RESULTS: Weight at diagnosis showed a positive association with severe functional limitation in stair climbing; however, a negative association was observed for weight change since age 40. Further analysis indicated that the association with weight at age 40 (highest vs. lowest quartile, OR=2.84, 95% confidence interval: 1.03-7.83, trend p=0.071) is stronger than weight at diagnosis. Other significant characteristics were age (70+ vs. 40-59 years, OR=7.37), previous knee pain and/or swelling 12 years or more before diagnosis (OR=2.67), and physical work (OR=1.94). In addition, higher parity was found to be a negatively associated factor (for tripara or more, OR=0.41). CONCLUSIONS: This study identified factors, such as heavy weight at age 40 and physical labor, which are potentially useful for preventing severe functional limitation for female knee OA patients. In addition, higher parity was associated with milder stair climbing limitation.

Distal femoral cut perpendicular to the mechanical axis may induce varus instability in flexion in medial osteoarthritic knees with varus deformity in total knee arthroplasty: a pitfall of the navigation system.

Two factors that influence the external rotation angle of the femoral rotational axis in total knee arthroplasty (TKA) were assessed in 40 medial osteoarthritic knees with varus deformity. First, the anatomic configuration of the femur was assessed using standardized radiographs of the patients' lower extremities before TKA. Second, the degree of medial soft tissue release was assessed during TKA. The radiographs showed that the characteristics of the femur were lateral bowing of the shaft and external rotation of the condyle in the coronal plane. Therefore, when the distal femur is cut perpendicular to the mechanical axis, the cut surface may be in too much of a valgus position. Furthermore, some degree of medial soft tissue release was necessary in all knees. Medial soft tissue release rotates the femur externally in extension in the coronal plane, and it rotates the femur externally around the femoral axis in flexion relative to the tibia. A distal femoral cut in too much of a valgus position and medial soft tissue release induces varus instability in flexion in knees with lateral bowing of the femoral shaft. Anatomic variation such as femoral bowing should be considered when a navigation system is used for TKA because the navigation system shows only the mechanical axis.

Distance of the femorotibial joint gap can be controlled in the modified ligament dependent cut procedure during total knee arthroplasty.

During total knee arthroplasty in fifty consecutive cases, the distal femur and proximal tibia were initially cut. After posterior cruciate ligament excision, the femorotibial joint was expanded by a Tensor/balancer device with 30 inch-pounds of torque (in.lbs) both in extension and flexion, and ligament balancing was obtained in full extension. Then the knee was flexed at 90 degrees, and the femoral rotational axis was decided so that the axis was parallel to the tibial cut surface and the joint gap was the same between extension and flexion. The relationship between the distance of the joint gap expanded by a Tensor/balancer device with 30 in.lbs and the size of the bearing insert was assessed. The results showed that a 24 or 25-mm joint gap expanded by a Tensor/balancer device in full extension was optimal for a 10-mm bearing insert. Therefore, if the resection level of the tibia is set 24 or 25 mm from the femoral cut surface, a 10-mm bearing insert can be used. In 49 cases, the size of the femoral component was one size (4 mm) larger than that predicted based on the bony structure shown in the radiographs of the knee. With this procedure, ligament balancing and optimal joint gap both in extension and flexion can be obtained based on the predicted bearing insert in the knee.